<template>
  MyLeft组件
  <div>
    count值为： {{ count }}
    <button @click="count++">+1</button>
  </div>
</template>
<script setup>
import { ref, onMounted, onUnmounted, onActivated, onDeactivated } from "vue";
const count = ref(0);
onMounted(() => {
  console.log("MyLeft组件被挂载了");
});
onUnmounted(() => {
  console.log("MyLeft组件被销毁了");
});

onActivated(() => {
  console.log('MyLeft组件被激活了')
})
onDeactivated(() => {
  console.log('MyLeft组件被缓存了')
})
</script>
